We tend to think of videos made by public agencies as staid, safe and dull. Not so the latest clip from the Denver Police Department showing law enforcers simulating an active shooter situation in a building at the old University Hospital site. The footage includes gunshots, explosions, hysterical screaming, open wounds, draining blood and bodies everywhere, supplemented by looks behind the scenes and one participant's analysis of what officers did wrong. The result may be the first public-service video that's not safe for work. See it below.